A design method of plate-fin evaporator based on evaporation heat absorption

Abstract

The application discloses a design method of a plate-fin evaporator based on evaporation heat absorption, relates to the technical field of heat exchanger design, and comprises the following steps: obtaining design requirements; presetting structure data of the evaporator according to performance requirements; calculating a Reynolds number according to fin structure parameters and medium parameters; calculating a total heat transfer coefficient according to a total heat transfer area of the evaporator, a heat transfer coefficient, a surface efficiency and a baffle thermal resistance; calculating a logarithmic heat transfer temperature difference according to the performance requirements; under the condition of meeting a required refrigerating capacity, calculating an effective heat exchange area required by the evaporator according to the logarithmic heat transfer temperature difference and the total heat transfer coefficient; and if the effective heat transfer area is less than the effective heat exchange area required by the evaporator, adjusting the structure data until the effective heat transfer area is not less than the effective heat exchange area required by the evaporator. The application couples a phase change heat transfer characteristic relation formula and a non-phase change plate-fin heat exchanger design model with each other, and solves the problem of complex calculation in the plate-fin evaporator design process.

Description

Technical Field

[0001] This application relates to the field of heat exchanger design technology, and in particular to a design method for a plate-fin evaporator based on evaporative heat absorption. Background Technology

[0002] An evaporator is a heat-absorbing device where refrigerant, as a liquid, boils at a relatively low temperature, turning into vapor and absorbing heat emitted by the object or space being cooled, thus achieving the purpose of refrigeration. Based on the type of medium being cooled, evaporators are mainly divided into air-cooled evaporators and liquid-cooled evaporators. Air-cooled evaporators often use a serpentine tube structure; liquid-cooled evaporators often use a shell-and-tube structure. Because traditional evaporators mostly use a tubular heat transfer structure, this structure is not entirely suitable for scenarios with limited installation space and high refrigeration requirements.

[0003] Plate-fin heat exchangers feature a finned structure that allows for secondary heat transfer, resulting in a compact structure, large heat transfer area per unit volume, and high heat transfer efficiency. Therefore, employing a plate-fin heat transfer structure in evaporator design can further improve the evaporator's cooling efficiency. Furthermore, plate-fin heat exchangers can be customized to meet specific customer size requirements, making them suitable for various complex applications.

[0004] However, plate-fin evaporators contain a cooling medium channel and a refrigerant channel. The cooling medium is a non-phase-change medium, such as air or liquid that needs to be cooled, while the refrigerant absorbs heat through evaporation phase change. In the evaporator design process, both the non-phase-change cooling medium and the evaporating refrigerant need to be considered simultaneously, which makes the calculations in the design process more complicated. Summary of the Invention

[0005] This application provides a design method for a plate-fin evaporator based on evaporative heat absorption, which solves the problem of complex calculations caused by simultaneously considering the cooled medium without phase change and the refrigerant with evaporative phase change in the evaporator design process in the prior art.

[0006] This application provides a design method for a plate-fin evaporator based on evaporative heat absorption, including:

[0007] Obtain the design requirements, which include media parameters and performance requirements;

[0008] The structural data of the evaporator is preset according to the performance requirements. The structural data includes fin structure parameters and baffle structure parameters.

[0009] Calculate the minimum free flow area and equivalent diameter based on the fin structure parameters;

[0010] Calculate the mass flow rate based on the minimum free flow area;

[0011] Calculate the Reynolds number based on the mass flow rate and equivalent diameter;

[0012] Calculate the heat transfer coefficient of the refrigerant based on the medium parameters;

[0013] The heat transfer coefficient of the cooled medium is calculated based on Prandtl number, mass flow rate and medium parameters, and the fin efficiency is calculated based on the heat transfer coefficients of the refrigerant and the cooled medium.

[0014] Calculate the total heat transfer area based on the primary and secondary heat transfer areas of the evaporator.

[0015] The effective heat transfer area is calculated based on the primary heat transfer area, the secondary heat transfer area, and the fin efficiency.

[0016] Surface efficiency is calculated based on secondary heat transfer area, total heat transfer area, and fin efficiency.

[0017] Calculate the wall thermal resistance based on the partition structure parameters and the primary heat transfer area;

[0018] The total heat transfer coefficient is calculated based on surface efficiency, total heat transfer area, wall thermal resistance, heat transfer coefficient of refrigerant, and heat transfer coefficient of the cooled medium.

[0019] Calculate the logarithmic heat transfer temperature difference based on performance requirements;

[0020] To meet the required cooling capacity, the effective heat exchange area of ​​the evaporator is calculated based on the logarithmic heat transfer temperature difference and the overall heat transfer coefficient.

[0021] Compare the effective heat transfer area with the effective heat exchange area required by the evaporator. If the effective heat transfer area is less than the effective heat exchange area required by the evaporator, adjust the structural data until the effective heat transfer area is greater than or equal to the effective heat exchange area required by the evaporator.

[0022] The design method of a plate-fin evaporator based on evaporative heat absorption in this application has the following advantages:

[0023] 1. The phase change heat transfer characteristic relationship is coupled with the design model of plate-fin heat exchanger without phase change to solve the problem of complex calculation in the design of plate-fin evaporators.

[0024] 2. It improves the evaporator's cooling efficiency and is suitable for various complex spatial scenarios.

[0025] 3. Using plate-fin heat exchangers for evaporative refrigeration expands the application range of plate-fin heat exchangers. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 A flowchart illustrating a design method for a plate-fin evaporator based on evaporative heat absorption, provided for an embodiment of this application.

[0028] Figure 2 A schematic diagram of the structure of the plate-fin evaporator designed for an embodiment of this application.

[0029] Figure 3 This is a schematic diagram of the fin arrangement on the refrigerant side provided in an embodiment of this application.

[0030] Figure 4 This is a schematic diagram of the fin arrangement on the side of the cooled medium provided in an embodiment of this application. Detailed Implementation

[0031] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0032] Figure 1 A flowchart illustrating a design method for a plate-fin evaporator based on evaporative heat absorption, provided in this application embodiment. This application embodiment provides a design method for a plate-fin evaporator based on evaporative heat absorption, comprising:

[0033] S100, Obtain design requirements, which include media parameters and performance requirements.

[0034] For example, the medium parameters include the type of medium, evaporation temperature, flow rate, density, specific heat capacity at constant pressure, thermal conductivity, dynamic viscosity, latent heat of vaporization, tension, and dryness. Since the evaporator in this embodiment includes a cooled medium side and a refrigerant side, it is necessary to obtain the medium parameters of the cooled medium and the refrigerant separately.

[0035] The performance requirements apply to the entire evaporator and mainly include data such as inlet and outlet temperatures, inlet and outlet flow rates, and inlet and outlet pressure differences.

[0036] S101, the structural data of the evaporator is preset according to the performance requirements. The structural data includes fin structural parameters and baffle structural parameters.

[0037] For example, the fin structure parameters mainly include the fin form, fin pitch, fin height, fin spacing, number of fin layers, and fin thickness, while the diaphragm structure parameters mainly include the diaphragm spacing and diaphragm thickness.

[0038] In addition to the two parameters mentioned above, the cover plate thickness and seal width also need to be obtained.

[0039] On the hot side of the evaporator, i.e., the side of the medium being cooled, there is no phase change, while on the cold side, i.e., the side of the refrigerant, the medium undergoes an evaporative phase change. The refrigerant removes heat from the cooled medium through evaporation and heat absorption. Since the refrigerant primarily absorbs heat through evaporation, the flow pattern has little impact on heat transfer; therefore, straight fins are used on this side. The heat transfer of the cooled medium is convective; therefore, the fin type used on this side is selected rationally based on the refrigeration requirements. Specifically, serrated fins are recommended for media with high viscosity and low flow rate, while straight fins are recommended for media with low viscosity and high flow rate.

[0040] S102, calculate the minimum free flow area and equivalent diameter based on the fin structure parameters.

[0041] For example, hydraulic radius Defined as minimum free flow area With wet week The ratio:

[0042]

[0043] in, The width of the fin channel. This represents the height of the fin channel.

[0044] Equivalent diameter Defined as 4 times the ratio of the minimum free flow area to the wetted perimeter:

[0045] Straight fins:

[0046]

[0047] Serrated fins:

[0048]

[0049] in, For fin pitch, The height of the fin. Minimum fin thickness, The discontinuity length of the serrated fin.

[0050] porosity Defined as minimum free flow area With windward area The ratio:

[0051]

[0052] S103, calculate the mass flow rate based on the minimum free flow area.

[0053] For example, mass flow rate As shown below:

[0054]

[0055] in, For mass flow rate.

[0056] S104, calculate the Reynolds number based on the mass flow rate and equivalent diameter.

[0057] For example, the Reynolds number As shown below:

[0058]

[0059] in, denoted as the dynamic viscosity of the fluid.

[0060] S105, calculate the heat transfer coefficient of the refrigerant based on the medium parameters.

[0061] For example, the heat transfer coefficient of the refrigerant Represented as:

[0062]

[0063] in, For liquid phase heat capacity, For heat flux density, Latent heat of vaporization For pressure, The thermal conductivity of the liquid phase is... The density of the liquid phase is... This represents the gas phase density.

[0064] S106 calculates the heat transfer coefficient of the cooled medium based on Prandtl number, mass flow rate, and medium parameters, and calculates the fin efficiency based on the heat transfer coefficients of the refrigerant and the cooled medium.

[0065] For example, the Prandtl number As shown below:

[0066]

[0067] in, Specific heat capacity of the fluid denoted as , where is the thermal conductivity of the fluid.

[0068] Heat transfer coefficient of the cooled medium Represented as:

[0069] or

[0070] in, j For heat transfer factor, Nu For Nusselt numbers.

[0071] Fin efficiency As shown below:

[0072]

[0073] in, For fin parameters, This represents the fin height.

[0074] Straight fins:

[0075]

[0076] Serrated fins:

[0077]

[0078] in, for and The general term, is the thermal conductivity of the material.

[0079] S107, calculate the total heat transfer area based on the primary and secondary heat transfer areas of the evaporator.

[0080] For example, the total heat transfer area Represented as:

[0081]

[0082] Among them, the primary heat transfer area This refers to the heat transfer area between the cold and hot fluids between the partitions. The primary heat transfer area is numerically the same for both the cold and hot fluids. Secondary heat transfer area... This refers to the area through which hot and cold fluids transfer heat via the fins.

[0083] S108, calculate the effective heat transfer area based on the primary heat transfer area, secondary heat transfer area and fin efficiency.

[0084] For example, effective heat transfer area Represented as:

[0085]

[0086] S109, calculate the surface efficiency based on the secondary heat transfer area, the total heat transfer area, and the fin efficiency.

[0087] For example, surface efficiency Represented as:

[0088]

[0089] S110, calculate the wall thermal resistance based on the partition structure parameters and the primary heat transfer area.

[0090] For example, wall thermal resistance Represented as:

[0091]

[0092] in, For the thickness of the partition, is the thermal conductivity of the partition.

[0093] S111, the total heat transfer coefficient is calculated based on surface efficiency, total heat transfer area, wall thermal resistance, heat transfer coefficient of refrigerant and heat transfer coefficient of the cooled medium.

[0094] For example, the overall heat transfer coefficient K The calculation formula is:

[0095]

[0096] S112, calculate the logarithmic heat transfer temperature difference according to performance requirements.

[0097] For example, logarithmic heat transfer temperature difference Represented as:

[0098]

[0099] in, The inlet temperature of the medium being cooled. The outlet temperature of the cooled medium. This is the evaporation temperature of the refrigerant.

[0100] S113, while meeting the required cooling capacity, calculates the effective heat exchange area required by the evaporator based on the logarithmic heat transfer temperature difference and the overall heat transfer coefficient.

[0101] For example, the required cooling capacity It can be represented as:

[0102]

[0103] in, The effective heat exchange area required by the evaporator to meet the required cooling capacity.

[0104] S114. Compare the effective heat transfer area with the effective heat exchange area required by the evaporator. If the effective heat transfer area is less than the effective heat exchange area required by the evaporator, adjust the structural data until the effective heat transfer area is greater than or equal to the effective heat exchange area required by the evaporator.

[0105] For example, the effective heat exchange area required by the evaporator to meet the required cooling capacity is calculated using the formula in S108. Then compare ,like If the evaporator design meets the requirements, then the evaporator design is satisfactory. Adjust the fin specifications and partition spacing, and redesign and recalculate until... .

[0106] Furthermore, after adjusting the fin size and baffle spacing, it is also necessary to calculate the flow resistance on the side of the cooled medium. Since the refrigerant side mainly undergoes an evaporation phase change process, and the refrigerant changes from a liquid phase to a gas phase, the gaps between molecules increase sharply, leading to a sharp increase in internal pressure. Therefore, it is impossible to accurately calculate the flow resistance on the refrigerant side.

[0107] Flow resistance on the side of the cooled medium The calculation is as follows:

[0108]

[0109] in, For specific volume, As the friction factor, The length is the flow length.

[0110] Furthermore, after ensuring that the effective heat transfer area is greater than or equal to the effective heat exchange area required by the evaporator, the thickness of the fins, the thickness of the baffles, and the width of the seals are checked.

[0111] The verification of fin thickness includes:

[0112] Obtain the maximum pressure resistance corresponding to the fin material;

[0113] The minimum fin thickness is calculated based on the maximum pressure resistance, fin structure parameters, and allowable stress of the fin material:

[0114]

[0115] in, For maximum withstand pressure, For allowable stress, The opening weakening factor is 1 (for straight and serrated fins). This is an additional amount for wall thickness.

[0116] Compare the thickness data in the fin structure parameters with the minimum fin thickness. If the thickness data in the fin structure parameters is greater than the minimum fin thickness, then the fin thickness is checked.

[0117] The methods for calculating the allowable stress of fin materials include:

[0118] Obtain the ultimate strength of the fin material, which includes the tensile strength and yield strength of the fin.

[0119] Calculate the allowable tensile stress and allowable yield stress of the fin corresponding to its tensile strength and yield strength, respectively, based on the fin's tensile strength, yield strength, and corresponding safety factors:

[0120]

[0121]

[0122] in, and These are the allowable tensile stress and allowable yield stress of the fin, respectively. For the tensile strength of the fins, For fin yield strength, and These are the safety factors for tensile strength and yield strength, respectively.

[0123] The smaller of the allowable tensile stress and the allowable yield stress of the fin is selected as the final allowable stress.

[0124] The verification of the thickness of the partition includes:

[0125] Obtain the maximum pressure resistance corresponding to the partition material;

[0126] The minimum thickness of the partition is calculated based on the maximum pressure resistance, fin structure parameters, and allowable stress of the partition material. :

[0127]

[0128] Compare the thickness data in the partition structure parameters with the minimum thickness of the partition. If the thickness data in the partition structure parameters is greater than the minimum thickness of the partition, then the thickness of the partition is checked.

[0129] Verifying the width of the seal includes:

[0130] Obtain the maximum pressure resistance corresponding to the seal material;

[0131] The minimum width of the seal is calculated based on the maximum pressure resistance, seal structure parameters, and allowable stress of the seal material. :

[0132]

[0133] in, s This refers to the thickness of the seal.

[0134] Compare the width data in the seal structure parameters with the minimum seal width. If the width data in the seal structure parameters is greater than the minimum seal width, then the seal width is checked.

[0135] Furthermore, the methods for calculating the allowable stress of the partition and sealing materials include:

[0136] Obtain the ultimate material strength corresponding to the materials of the partition and the seal;

[0137] The allowable stress is calculated based on the material's ultimate strength and the corresponding safety factor.

[0138] Design Example:

[0139] 1. Design Requirements

[0140] Evaporator hot-side medium: 65# coolant, flow rate 300L / min, outlet temperature 49.5℃.

[0141] Evaporator cold side medium: R134a, flow rate 0.42kg / s, inlet dryness fraction 0.481, evaporation temperature 44.5℃, superheat 1℃.

[0142] Evaporator heat exchange capacity: ≥35kW.

[0143] Refrigerant side: gas tightness pressure ≥3.5MPa, pressure resistance pressure ≥5.25MPa.

[0144] Cooled medium side: airtight pressure ≥ 0.86 MPa, pressure resistance ≥ 1.29 MPa.

[0145] Evaporator structure as follows Figure 2 As shown.

[0146] 2. Pre-designed structural data of the evaporator core

[0147] Based on the performance and size requirements of the evaporator's hot and cold sides, the evaporator core structure is pre-designed, as shown in Table 1.

[0148] Table 1 Evaporator Core Structure Dimensions

[0149]

[0150] 3. Medium parameters

[0151] The physical properties of the cooled medium and refrigerant are shown in Table 2.

[0152] Table 2. Medium parameters under extreme conditions

[0153]

[0154] 4. Calculation Results

[0155] Subscript 1 indicates the side of the medium being cooled, and subscript 2 indicates the side of the refrigerant. The calculation results are as follows:

[0156] Equivalent diameter: .

[0157] Minimum free flow area: .

[0158] Mass flow rate: .

[0159] Reynolds number: .

[0160] Prandtl number: .

[0161] Based on Weiting's empirical formula for heat transfer and pressure drop in serrated fins, the heat transfer factor is calculated as follows: Fanning friction factor: .

[0162] Heat transfer coefficient: ; .

[0163] Fin efficiency: .

[0164] Total heat transfer area: .

[0165] Effective heat transfer area: .

[0166] Surface efficiency: .

[0167] Overall heat transfer coefficient: K =3610.4 .

[0168] Logarithmic mean temperature difference: .

[0169] The required effective heat exchange area of ​​the evaporator to meet the required cooling capacity. .

[0170] Friction resistance along the flow path: .

[0171] Conclusion: Comparison and It can be found that, > Therefore, the evaporator structure design meets the heat exchange index.

[0172] 5. Strength verification

[0173] The evaporator's baffles, cover plates, and seals are made of 3A21-H18 material, while the fins are made of 3003-H16 material. Their ultimate strength conforms to GB / T 3880.2 "General Industrial Aluminum and Aluminum Alloy Plates and Strips - Part 2: Mechanical Properties," as shown in Table 3 below. According to GB 150.1 "Pressure Vessels - Part 1: General Requirements," the safety factors for the tensile strength and yield strength of the aluminum alloy are 3.0 and 1.5, respectively.

[0174] Table 3 Ultimate Strength of Aluminum Alloy Materials

[0175]

[0176] Allowable stress of partitions, covers, and seals:

[0177] MPa

[0178] Allowable stress of fins:

[0179] MPa

[0180] MPa

[0181] The minimum value between the two is taken, which is the allowable stress of the fin. = =56.67MPa.

[0182] 5.1 Fin Thickness Verification

[0183] The fins are made of 3003-H16. Based on GB / T 3198 "Aluminum and Aluminum Alloy Foil", the allowable thickness deviation for aluminum foil with a thickness of 0.009mm to 0.2mm is 5%, and the thickness is calculated as follows:

[0184]

[0185] In the formula: P The value is 5.25 MPa. The value is 1.35mm. The value is 56.67 MPa. The value is 1.

[0186] The thickness data in the fin structure parameters is 0.15mm, and the strength meets the requirements.

[0187] 5.2. Check the thickness of the partition plate

[0188] The partition plate is made of 3A21-H18 aluminum alloy. Based on GB / T 3880.3 "General Industrial Aluminum and Aluminum Alloy Plates and Strips - Part 3: Dimensional Deviations", the processing deviation for plates with a thickness of 0.6mm to 0.8mm is 0.05mm. Therefore, the wall thickness correction factor is taken as 0.05mm, and the thickness is calculated as follows:

[0189]

[0190] In the formula: P The value is 5.25 MPa. Take a value of 1.5mm. The value is 61.67 MPa. The value is 0.05mm.

[0191] The thickness data in the partition structure parameters is 0.5mm, and the strength meets the requirements.

[0192] 5.3 Seal Width Verification

[0193] The sealing strip is 3A21-H18. Based on GB / T 3880.3 "General Industrial Aluminum and Aluminum Alloy Plates and Strips - Part 3: Dimensional Deviations", the processing deviation for plates with a thickness of 1.8mm to 2.0mm is 0.09mm. Therefore, the wall thickness correction factor is taken as 0.09mm, and the thickness is calculated as follows:

[0194]

[0195] In the formula: P The value is 5.25 MPa. Take the value 2mm. The value is 61.67 MPa. The value is 0.09 mm.

[0196] The width of the seal is 5mm, and its strength meets the requirements.

[0197] The final fin arrangement of the refrigerant side and the cooled medium side is as follows: Figure 3 and 4 As shown.

[0198] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0199] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A design method for a plate-fin evaporator based on evaporative heat absorption, characterized in that, include: Obtain design requirements, which include medium parameters and performance requirements. The medium parameters include the parameters of the medium being cooled and the liquid phase heat capacity, heat flux density, latent heat of vaporization, pressure, liquid phase thermal conductivity, liquid phase density, and gas phase density of the refrigerant. The structural data of the evaporator is preset according to the performance requirements, and the structural data includes fin structure parameters and baffle structure parameters. Calculate the minimum free flow area and equivalent diameter based on the fin structure parameters; Calculate the mass flow rate based on the minimum free flow area; Calculate the Reynolds number based on the mass flow rate and the equivalent diameter; The heat transfer coefficient of the refrigerant is calculated based on the aforementioned medium parameters. Represented as: in, For liquid phase heat capacity, For heat flux density, Latent heat of vaporization For pressure, The thermal conductivity of the liquid phase is... For porosity, The density of the liquid phase is... This refers to the gas phase density. The heat transfer coefficient of the cooled medium is calculated based on the Prandtl number, the mass flow rate, and the medium parameters; the fin efficiency is calculated based on the heat transfer coefficients of the refrigerant and the cooled medium. Calculate the total heat transfer area based on the primary and secondary heat transfer areas of the evaporator. The effective heat transfer area is calculated based on the primary heat transfer area, the secondary heat transfer area, and the fin efficiency. Surface efficiency is calculated based on the secondary heat transfer area, the total heat transfer area, and the fin efficiency. Calculate the wall thermal resistance based on the partition structure parameters and the primary heat transfer area; The total heat transfer coefficient is calculated based on the surface efficiency, the total heat transfer area, the wall thermal resistance, the heat transfer coefficient of the refrigerant, and the heat transfer coefficient of the cooled medium. Calculate the logarithmic heat transfer temperature difference based on the performance requirements; Under the condition of meeting the required cooling capacity, the effective heat exchange area required by the evaporator is calculated based on the logarithmic heat transfer temperature difference and the total heat transfer coefficient. Compare the effective heat transfer area with the effective heat exchange area required by the evaporator. If the effective heat transfer area is less than the effective heat exchange area required by the evaporator, adjust the structural data until the effective heat transfer area is greater than or equal to the effective heat exchange area required by the evaporator.

2. The design method of a plate-fin evaporator based on evaporative heat absorption according to claim 1, characterized in that, The refrigerant side uses straight fins, while the cooled medium side uses either serrated or straight fins depending on the viscosity and flow rate of the cooled medium.

3. The design method of a plate-fin evaporator based on evaporative heat absorption according to claim 1, characterized in that, The formula for calculating the overall heat transfer coefficient is as follows: in, K This represents the overall heat transfer coefficient. A This represents the total heat transfer area. This represents the surface efficiency. This represents the heat transfer coefficient on the side of the cooled medium. This indicates the wall thermal resistance. This represents the heat transfer coefficient on the refrigerant side.

4. The design method of a plate-fin evaporator based on evaporative heat absorption according to claim 1, characterized in that, After the effective heat transfer area is greater than or equal to the effective heat exchange area required by the evaporator, the thickness of the fins, the thickness of the baffle, and the width of the seal are checked.

5. The design method of a plate-fin evaporator based on evaporative heat absorption according to claim 4, characterized in that, The verification of fin thickness includes: Obtain the maximum pressure resistance corresponding to the fin material; The minimum fin thickness is calculated based on the maximum withstand pressure, the fin structure parameters, and the allowable stress of the fin material. The thickness data in the fin structure parameters is compared with the minimum fin thickness. If the thickness data in the fin structure parameters is greater than the minimum fin thickness, the fin thickness is verified.

6. The design method of a plate-fin evaporator based on evaporative heat absorption according to claim 5, characterized in that, The methods for calculating the allowable stress of fin materials include: Obtain the ultimate strength of the fin material, wherein the ultimate strength of the fin includes the tensile strength and the yield strength of the fin. Calculate the allowable tensile stress and allowable yield stress of the fin corresponding to the tensile strength and yield strength of the fin, respectively, based on the tensile strength and yield strength of the fin and the corresponding safety factor. The smaller value between the allowable tensile stress of the fin and the allowable yield stress of the fin is selected as the final allowable stress.

7. The design method of a plate-fin evaporator based on evaporative heat absorption according to claim 4, characterized in that, The verification of the thickness of the partition includes: Obtain the maximum pressure resistance corresponding to the partition material; The minimum thickness of the partition is calculated based on the maximum pressure resistance, the fin structure parameters, and the allowable stress of the partition material. Compare the thickness data in the partition structure parameters with the minimum thickness of the partition. If the thickness data in the partition structure parameters is greater than the minimum thickness of the partition, then the thickness of the partition is verified.

8. The design method of a plate-fin evaporator based on evaporative heat absorption according to claim 7, characterized in that, Verifying the width of the seal includes: Obtain the maximum pressure resistance corresponding to the seal material; The minimum width of the seal is calculated based on the maximum pressure resistance, seal structure parameters, and allowable stress of the seal material. The width data in the seal structure parameters is compared with the minimum width of the seal. If the width data in the seal structure parameters is greater than the minimum width of the seal, the width of the seal is verified.

9. The design method of a plate-fin evaporator based on evaporative heat absorption according to claim 8, characterized in that, The methods for calculating the allowable stress of partition and sealing materials include: Obtain the ultimate material strength corresponding to the materials of the partition and the seal; The allowable stress is calculated based on the ultimate strength of the material and the corresponding safety factor.

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